The DENDRAL project begins
Stanford began building a system that identifies the structure of an organic molecule from its mass spectrum, using rules supplied by chemists.
Why it matters
The field recovered results by trading general search for a narrow task filled with expert knowledge.
DENDRAL demonstrated what Feigenbaum later stated outright: a system's power comes from domain knowledge, not from the elegance of its inference mechanism. Rules were extracted from chemists in long interviews, and that labour created the separate problem of knowledge acquisition. Meta-DENDRAL later tried to derive the rules automatically.